Capsules containing beverage ingredients and designed for producing a beverage in a beverage preparation device upon liquid injection into the capsules and by rotating the capsules around their central axis in the device are known.
The principle consists in preparing a beverage by passing a liquid through beverage ingredients contained in the capsule using centrifugal forces. Thereby, liquid is usually injected in a central inlet area of the capsule before and/or during rotation of the capsule in order to make the liquid interact with the ingredients in the capsule, thereby forming a beverage such as coffee, ground coffee, tea and the like. The resulting beverage is then allowed to exit the capsule by means of at least one outlet aperture provided at a portion arranged peripherally and radially outwards with respect to the central inlet area of the capsule.
A capsule for preparing a beverage or liquid food and a system using centrifugal forces is for example described in WO2008/148650. The capsule is formed of a body containing a substance such as coffee powder which is closed by a lid member and a membrane. The membrane is perforated by an injection member of a beverage preparation device in the central part of the membrane for injection of liquid. The capsule further comprises outlet openings arranged at a substantially peripheral portion of the lid member of the capsule for enabling the prepared beverage to leave the capsule under the centrifugal forces exerted in the capsule during beverage preparation.
The capsule according to the prior art suffers the drawback that during injection of liquid into the capsule by means of a dedicated injection member of the beverage preparation device, the upper wall or lid member of the capsule may be deformed or even broken due to a lack of support in the centrifugal brewing chamber of the device.
A lack of support may come from a possible or needed distance between the lid and a rotary engagement member of the device. For instance, a distance or gap between the capsule (i.e., the lid of the capsule) and the rotary engagement member may be needed to allow a sufficient room for the beverage to flow towards the collecting means of the beverage preparation device.
However, the pressure of liquid in the capsule increase gradually from the centre to the periphery of the lid due to the generated centrifugal forces and the pressure of liquid may reach high values at the periphery during the beverage extraction operation. If the lid is not supported enough or well due to the distance, it may be damaged (e.g., torn or ruptured) or may be forced to disconnect from the rest of the capsule.
Therefore, a capsule is sought-after which enables the reliable preparation of a beverage by means of centrifugation within a dedicated beverage preparation device.
The present invention seeks to address the above described problems. The invention also aims at other objects and particularly the solution of other problems as will appear in the rest of the present description.